"I hope the prime minister's able to sort out this particular embarrassment and incompetence," Mr Shorten told reporters in the Northern Territory on Monday.

"You don't rush out and say we're going to stop this fellow by one particular legal mechanism, and close the back door and square it off with the Fijian government."

Mr Morrison is also expected to discuss Australian funding for a major regional military base while he is in Fiji.

The coalition government has contributed a significant figure to transform the Black Rock Camp in Nadi into a regional training hub for South Pacific militaries.

Mr Morrison will also travel to Vanuatu, in the first trip to the country by an Australian prime minister outside the Pacific Islands Forum.

"This is part of our Pacific step-up. It's part of our refocusing of our international efforts on our own region, in our own backyard, and making sure we can make the biggest possible difference," Mr Morrison said.